1. Technical Field
The present invention relates to a functional element, an electronic apparatus, and a moving object.
2. Related Art
In recent years, functional elements (physical quantity sensors) that detect a physical quantity such as acceleration have been developed using, for example, a silicon MEMS (Micro Electro Mechanical Systems) technique.
For example, JP-A-2007-298405 discloses an electrostatic capacitive sensor including a first movable electrode and a first fixed electrode. The first movable electrode is movably supported to a fixed portion of a semiconductor layer via a beam portion so as to have an asymmetric mass balance, and operates in response to a change in physical quantity in the thickness direction of the semiconductor layer. The first fixed electrode is formed on a support substrate that supports the semiconductor layer. The first movable electrode and the first fixed electrode are disposed to face each other via a gap. The electrostatic capacitive sensor detects a physical quantity based on an electrostatic capacitance detected according to the size of the gap between the first movable electrode and the first fixed electrode.
In such a functional element, in the manufacture of the functional element for example, a potential difference occurs between the movable electrode and the support substrate, the movable electrode is attracted to the support substrate side with an electrostatic force, and therefore, the movable electrode sticks to the support substrate in some cases. Especially when a lid (cap) for sealing the movable electrode and the support substrate are anodically bonded together, a large potential difference occurs between the movable electrode and the support substrate, which is problematic.
In the electrostatic capacitive sensor disclosed in JP-A-2007-298405, a stopper for avoiding direct contact with the support substrate is provided on a surface of the movable electrode facing the support substrate for preventing the movable electrode from sticking to the substrate.
In the electrostatic capacitive sensor disclosed in JP-A-2007-298405, however, since a surface of the support substrate facing the movable electrode has a large exposed region, the movable electrode sticks to the support substrate in some cases due to an electrostatic force between the exposed region and the movable electrode.